Addition products of heterocyclic nitrogen polymers and heavy metal salts, method ofimpregnating with, and impregnated article



Unite States Patent Ofi.

James E. Pritchard, Bartlesville, Okla., assignor to Phillips PetroleumCompany, a corporation of Delaware No Drawing. Application September 7,1954 Serial No. 454,615

23 Claims. (Cl. 117-1385) This application is a continuation-in-part ofSerial No. 329,450, filed January 2, 1953, and now abandoned, sameassignee.

This invention relates to reaction products of heterocyclic nitrogenbase polymers and salts of heavy metals having fungicidal and/orinsecticidal properties, the preparation of such products, and their usein rendering textiles and other absorbent materials waterproof andresistant to the attack of insects, larvae, fungi, bacteria and otherparasitic microorganisms. In a further aspect the invention relates towater repellent absorbent materials which areresistant to attack by theaforesaid organisms.

Absorbent materials such as textiles, paper, wood, hair, leather, fur,and the like are frequently damaged by bacteria, fungi, insects andtheir larvae, etc. Many methods of treatment have been proposed by whichsuch materials can be rendered resistant to these agents, but all leavesomething to be desired. For example, it is well known that salts ofheavy metals will, when applied to textiles, render them resistant tomildew and similar parasitic micro-organisms; but because of the easewith which these salts are removed from the fabric upon exposure tomoisture and weather conditions, the effect is not lasting duringservice conditions. The conventional solution to problems of this typehas been to first treat the material with a fungicide or otherparasiticide of this type and then to apply an organic compound whichwill'bind the fungicide to the material and render the latterwaterproof. A class of impregnants has now been discovered whichcombines these two functions in one treatment.

It is an object of this invention to provide compounds which, whenapplied to an absorbent surface such as textiles, render the latterWaterproof and resistant to parasiticidal organisms. A further object isto provide a method of preparing such compounds. An additional object isthe provision of a method of impregnating a textile or other absorbentmaterial with such compounds. Another object is the provision of textilefibers and other absorbent materials which are rendered water repellentand resistant to attacks of fungi, bacteria, insect larvae, etc.

In accordance with this invention it has been found that compoundsformed by the reaction of heterocyclic nitrogen base polymers with metalsalts having fungicidal and insecticidal properties unexpectedly retainthe fungicidal and insecticidal properties of the metal salts. Fibersimpregnated with these polymeric salts retain them during exposure tomoisture and weather conditions for a much longer period of time thanthey would retain the metal salts alone. In addition these impregnantsimpart to the fiber a high degree of water repellency and are notremoved during laundering and dry cleaning of the fibers. Theseimpregnants are easily applied, requiring only drying after applicationand do not require a special heat treatment to insure a permanentfinish,

Patented Nov. 25, 19 58 Because they impregnate the fibers instead offorming a coating on the surface of the treated materialthey arepreferred over many types of coatings which tend to break up or crackand which are therefore less permanent. These compositions can be usedas unsupported films suitable for use as Wrapping materials or astreating agents for absorbent material which is subject to attack of thetype described. The preferred metal salts are those of mercury, copper,and zinc. Other salts which are operative are those of barium, lead,bismuth, iron, cobalt, nickel, silver, gold, tin, arsenic, antimony,cadminum, and chromium.

The metal salts may be of the simple inorganic type, for example,chromic sulfate, cupric sulfate, cupric chloride, cadmium chloride, zincchloride, mercuric chloride, mercuric nitrate, etc. These salts arewater soluble and can, therefore, be employed for reactions in aqueoussolutions. Organic salts which are operative include the metal salts ofsaturated and unsaturated aliphatic carboxy acids, saturated andunsaturated alicyclic carboxy acids, and aromatic carboxy acids, thetotal number of carbon atoms in the acid not exceeding 20. Both monoanddibasic acids are. suitable. When the metal salt is not water soluble,it is dissolved in an organic solvent and the resulting solutionemployed in the reaction with the polymer of the pyridine derivative,since it is generally more desirable to effect these reactions insolution.

New compositions of this invention are prepared from polymers ofheterocyclic nitrogen bases of the pyridine and quinoline seriescontaining a vinyl or alphamethylvinyl group. Homopolymers, copolymers,terpolymers, etc, all produce valuable products. Monomerscopol'ymerizable with these heterojcyclic nitrogen bases includecompounds containing an active CH =C group. Examples of such compoundswhich are widely used include styrene; substituted styrenes, such asalkyl, alkoxy, and halogen-substituted styrenes; acrylonitrile;methacrylonitrile; methyl acrylate; methyl methacrylate; ethyl acrylate;butyl acrylate; conjugated dienes, and the like. Also, polymers can beprepared from various mixtures of these heterocyclic nitrogen basescontaining a vinyl or alpha-methylvinyl group, one or more conjugateddienes, and one or more polymjerizable materials containing the vinyl oralpha-methylvi'nyl group set forth above.

'"lihe polymericstarting materialscan range from liquid to rubbery tosolid resinous materials, depending upon the monomers employed and themethod of preparation. For example, copolymers of a conjugated dienewith a vinyl-pyridine, when prepared by emulsion polymeriza tion, canrange from liquid to rubbery products, depend.- ing .upon the amount ofmodifier employed in the polymerization recipe.

The heterocyclic nitrogen bases which are applicable for the productionof the polymericstarting materials are .thoseof the pyridine andquinoline series which are copolymerizable with a conjugated diene andcontain at least one substituents be methyl and/or ethyl.

The heterocyclic nitrogen bases are those having the formula win thegroup being not over 12, in addition to those carbon atoms in the vinyland/or alpha-methylvinyl groups. Examples of such compounds are2-vinylpyridine; 2-vinyl- S-ethylpyridine; 2,5-divinylpyridine;Z-methyl-S-vinylpyridine; 4 vinylpyridine; 2,3,4 trimethylvinylpyridine; 3,4,5 ,6-tetramethyl-2-vinylpyridine; 3-ethyl-5-vinylpyridine; 2,6-diethyl-4-vinylpyridine; 2-isopropyl-4-nonyl-5-vinylpyridine; 2-methyl-5-undecyl-3-vinylpy1'idine; 3-dodecyl 4,5divinylpyridine; 2,4 dimethyl 5,6 dipentyl- 3-vinylpyridine;2-decyl-5(alpha-methylvinyl) pyridine; 3,5-di(alpha-methylvinyl)pyridine; 3-nitro-2-vinylpyridine; 2-vinyl-4-hydroxy-5-nitropyridine;2-vinyl-3-methyl- S-ethylpyridine; 2-methoxy-4-chloro-6-vinylpyridine;3- vinyl 5 ethoxypyridine; 2 vinyl 4,5 dichloropyridine; 2 (alphamethylvinyl) 4 hydroxy 6 cyanopyridine;2-vinyl-4-phenoxy-S-methylpyridine; Z-cyano-S- (alpha-methylvinyl)pyridine; 3-vinyl-5-phenylpyridine;Z-(para-methylphenyl)-3-vinyl-4-methylpyridine; 3-vinyl-5-(hydroxyphenyl) pyridine; Z-VinyIquinoline; 2-vinyl-4- ethylquinoline;3 vinyl 6,7 di n propyl quinoline; 2 methyl 4 nonyl 6 vinylquinoline;4(alpha methylvinyl)-8-dodecylquinoline; 3-vinylisoquinoline;1,6-dimethyl-3-vinylisoquinoline; 2-vinyl-4-benzylquinoline; 3-

vinyl-S-chloroethylquinoline; 3-vinyl-5,6-dichloroisoquino-- line; 2vinyl 6 ethoxy 7 methylquinoline', 3 vinyl- 6-hydroxymethylisoquinoline;and the like.

,The conjugated dienes employed are preferably those which contain fromfour to six, inclusive, carbon atoms per molecule and include1,3-butadiene, isoprene, piperylene, methylpentadiene,2,3-dimethyl-1,3-butadiene, chloroprene, and others. However, conjugateddienes having more than six, such as eight, carbon atoms per moleculecan also be used. Furthermore, various alkoxy, such as methoxy andethoxy, and cyano derivatives of these conjugated dienes, are alsoapplicable. In fact, it has been found that when dealing with fabricssuch copolymers are more water repellent than the homopolymers describedabove. The explanation is that the heterocyclic nitrogen bases arewater-soluble whereas such olefins as butadiene are water-insoluble.Hence, the higher the content of heterocyclic base in relation todiolefin the greater the water-solubility of the polymer, and hence thelower is its water-repellency. Conversely, the greater the ratio ofdiolefin to heterocyclic base the greater the water-repellency of thepolymer. The conjugated diene component of the copolymer not onlyimparts water-repellency, but also gives greater flexibility, while thepyridine or quinoline derivative imparts low oil solubility to theproduct. I use from 25 to 75 parts by weight of the conjugated diolefinand from 75 to 25 parts by weight of the heterocyclic nitrogen base perparts by weight total monomers. A specific example of a copolymer whichimparts excellent water repellency characteristics to a fabric is a50/50 butadiene/2-methyl-5-vinylpyridine copolymer.

Preferred pyridine derivatives are 2-methyl-5-vinylpyridine,2-vinyl-5-ethylpyridine, and Z-Vinylpyridine. Using the first of thesecompounds, 2-methyl-5-vinylpyridine, the homopolymer has this structure:

and poly-2-vinylpyridine, this structure:

CHzCH-CHr-OHCHz-CH-GH2- The polymeric mercury and zinc metal salts ofthis invention are of two types and I believe that the particularproduct obtained is dependent upon the method by which the reaction iscarried out. In one of these products the metal atom of the salt isattached to the nitrogen atom of the pyridine nucleus. To illustratethese compounds only a pyridine nucleus will be illustrated but it is tobe understood that the balance of the polymer is present. Further, itshould be understood that not every pyridine nucleus need be reactedwith the particular salts, but that only a portion of these pyridinenuclei need have the salt reacted therewith. On this basis, illustrativetypes of compounds are:

and

where Y is a salt of a metal as defined above with an inorganic acid oran organic acid containing no more than 20 atoms, and A is the acid.Specific examples are:

inwtuiom ass-1,902

N/.HC1. ouol,

N .Ho1 2011011 N. ZnGl: I

N/. E on. H01

While the amount of metal in the polymeric salt may vary between widelimits the lower limit should be at least 5% to avoid having to apply anexcessive amount of polymeric salt to fabrics to obtain the necessaryfungicidal effect.

7 As stated above the determination of which of these two types ofcompounds is formed depends on how the reaction between the polymer andthe metal salt is eflected. Taking mercury as an example, the method offorming the two types of polymer will now be discussed. To distinguishthe two products, the one in which the mercury atom is attached to acarbon atom of the pyridine nucleus will be referred to as a mercuratedpolymer. The other type wherein the mercury salt is attached to thenitrogen atom of the pyridine nucleus will be referred to as a mercurycomplex.

Whether a nuclear substituted product or a polymeric complex compound isformed by reaction of the polymer with the mercuric salt depends largelyupon the method of preparation employed. For the preparation of mercurated compounds, i. e. nuclear substituted products, an acid solution ofthe polymer is treated with mercuric acetate andthe reaction mixture ismaintained at a temperature in the-range of 20 to 100 C. for a period inthe range of 1 minute to 24 hours, preferably 15 minutes to 2 hours. Thetime required is dependent upon the compounds reacted and the reactiontemperature. For this reaction the polymer is generally dissolved inacetic acid and the mercuric salt, also in solution, is added to thesolution of the polymer. When a mercurated product other than theacetate is desired, the acetate is generally prepared first and, bytreatment with a suitable reagent, the acetate is converted to thedesired product. For example, the acetate may be treated with sodiumchloride or sodium nitrate to yield the chloride, e. g.

or nitrate, e. g.

Treatment with an organic acid, or the sodium salt thereof, converts theacetate to the salt of the corresponding acid. Mercurated polymers areprecipitated from the reaction medium by the addition of an alkalinetreating agent such as an alkali metal hydroxide, carbonate orbicarbonate.

For the preparation of a complex salt of the polymer, such as is formedby reaction of the nitrogen atom of the pyridine nucleus with a mercuricsalt, mercuric chloride is generally preferred. The polymer is dissolvedin an acid, such as hydrochloric acid, and this solution is contactedwith the mercuric salt solution. These polymer complex compounds aregenerally of a very limited solubility in the reaction medium and,therefore, precipitate as they are formed.

The action of zinc salts is analogous to that of mercury, i. e. the Zincacetate attaches to a nuclear carbon whereas the zinc chloride attachesto the nitrogen atom of the pyridine nucleus.

When an aqueous acid solution of the pyridine derivative polymer isprepared prior to reaction with a metal salt, the acid solution of thedesired concentration is frequently prepared first, the polymer is thenadded, and the mixture is agitated to facilitate solution. Sometimes amore concentrated solution of acid is prepared first and the solutiondiluted to the desired concentration after the polymer is dissolved. Ininstances where an acid such as acetic acid is used, the polymer can betreated with the concentrated acid and the mixture diluted prior to use.Regardless of the acid concentration employed the polymer dissolves w1ththe formation of a pyridinium salt. Solvation of the polymeric materialcan in some instances be obtained when only one-fourth of thestoichiometric equivalent of acid to basic units in the polymer is usedbut larger amounts of acid, even up to several chemical equivalents, canbe used. The amount of acid is governed, at least partially, by the typeof polymer employed since the pyridinium salts of the polymer must beacid-solubie, in preparing an acid solution of a copolymer of1,3-butadiene and Z-methyl-S-Vinylpyridine, the content of butadieneshould not exceed parts by Weight, this being about the border line ofacid solubility. As previously stated a 50/50 mixture is preferred.

Acids which are applicable are those which possess sufiicient watersolubility to give solutions of the desired concentration. Bothsaturated and unsaturated aliphatic monobasic and dibasic organic acidscan be employed as well as mineral acids. Examples of acids in whichheterocyclic nitrogen base polymers can be dissolved include formic,acetic, propionic, butyrlc, oxalic, malonic, maleic, succinic, glutaric,glycolic, hydrochloric, sulfuric, nitric, and phosphoric. The acidity ofthe vinylpyridine polymer solutions is regulated so that the fabricsbeing treated will not be harmed. The pH is preferably in the range from2 to 6.

The metal salt complex of the heterocyclic nitrogen base can be appliedto the fabric in various Ways. In one method of operation, the fabric isimmersed in an aqueous acidic solution of the polymer. It is thensqueezed or centrifuged to remove excess moisture, followed by immersionin an aqueous solution of a salt, whereupon the insoluble complexprecipitates on and/or in the fabric. This is followed by rinsing witheither water or with a dilute base to remove combined acid. When thesalt complex is soluble in the acidic aqueous medium, the fabric must beimmersed in a solution of a basic material such as an alkali metalhydroxide, an alkali metal carbonate, or bicarbonate to precipitate thepolymer-salt complex before rinsing and drying the fabric. The alkalinetreating solution should be of such concentration that it will not harmthe material being treated. Preferably a concentration not greater thanone percent by weight is employed, or expressed in other terms, a 0.01to 0.25 normal solution.

In a specific embodiment of the invention, the first solution comprisesan aqueous acetic acid solution of a copolymer of butadiene with2-methyl-5-vinylpyridine, and the second solution comprises an aqueoussolution of zinc acetate. Immersion in an alkaline bath is thennecessary to cause precipitation of the complex.

When it is desired to impregnate an absorbent material with a mercuratedproduct, such as the mercuric acetate derivative of the polymer, it isconvenient to prepare a solution of the mercurated compound by adding anaqueous solution of mercuric acetate to an acetic acid solution of thepolymer and maintaining the mixture for a time and at a temperature toyield the nuclear-substituted product. The fabric is immersed in thissolution, squeezed by passing it through rollers or by other suitablemeans to remove excess solution, and then washed with a solution of abasic material such as the above mentioned alkali metal hydroxide,carbonate or bicarbonate. This treatment causes the mercurated polymerto be precipitated in the fabric. The fabric is then rinsed with Waterto remove excess basic solution and dried.

When it is desired to produce a fabric impregnated with the mercuriccomplex of the polymer, the absorbent material is first immersed in anaqueous acid solution of the polymer until it becomes saturated. Thenexcess solution is removed by passing the material between rollers or byother means, and then the absorbent material is immersed in an aqueoussolution of a mercuric salt which forms an insoluble complex with thepolymer, for example, mercuric chloride. Since the polymer mercuric saltcomplex is insoluble, the complex is precipitated in the absorbentmaterial, after which excess mercuric salt solution is removed bysqueezing and the impregnated material is dried.

Production of absorbent material impregnated with a mercurated polymerother than the acetate is accomplished by contacting the acetate withthe desired reagent before impregnating the absorbent material. Analternative method is to impregnate the material with the acetate andthen convert the treating agent to the desired mercurated compoundbefore washing the material with the alkaline solution.

Instead of employing aqueous solutions of the metal salts and aqueousacid solutions of the polymers, as described above, other solvents canbe used. Any solvent which is a solvent for both the polymer and themetal salt but is a non-solvent for the reaction product is applicable,e. g. alcohols, ethers, and hydrocarbons. In such case either thepolymer or its acid salt can be used. The metal salt can be dissolved inalcohol and the polymer can be dissolved in a mixture of an alcohol andan aqueous acid solution.

In' general, fabric is impregnated with the polymer metal saltcompositions in amounts ranging from 0.1 to 25 parts of the treatingagent per parts of the material treated, preferably from 0.5 to 5 partsby weight. The amount of treating agent applied to a fabric is dependentupon the type of fabric treated and the ultimate use.

Having thus outlined the objects and principles of my invention, thefollowing exemplifications thereof are furnished for the purposes ofillustration and not in limita: tion.

Poly-2-methyl-5-vinylpyridine 1) and a butadiene/Z-methyl-S-vinylpyridine copolymer (II) were prepared by emulsionpolymerization at 50 C. in accordance with the following recipes:

TABLE A 1 A blend of tertiary O12, C14, and On aliphatic mereaptans in aratio of 3:1:1 parts by weight.

The latex was shortstopped at an average conversion of 68% with 0.1 partdi-tert-butyl hydroquinone. As an antioxidant 2% by weight ofphenyl-beta-naphthaylamine based on the weight of the polymer was added.The brine-alcohol method of coagulation was used; then the polymer waswashed free of soap and dried.

Samples of 10-ounce cotton duck which had been laundered and dry cleanedto remove any sizing or finishing oils were treated in various ways ashereinafter described. One untreated sample was reserved as a control.After treatment, the samples were subjected to tests to determine theirresistance to fungi and other microorganisms and to weathering byatmospheric conditions. Water repellency was also determined on some ofthe samples.

Soil burial test In this test, fabric was buried for 30 days at roomtemperature in moist soil of the type capable of supporting good plantgro-wt Such soil contains among other microorganisms cellulosedestroying fungi and bacteria. At the end of 30 days, the reduction inbreaking strength of one-inch wide strips of fabric was measured.

Microbiological test for mildew resistance in this test the mildewresistance of strips of treated cotton duck was determined by measuringtheir reduction in breaking strength after inoculation and incubationwith the fungus Chaetomium globosum.

An inoculum of Chaetomium globosum was prepared by dispersing in Waterthe scrapings from a ripe fruiting culture.

Into eight ounce square bottles was poured a culture medium prepared bymixing together and heating in an autoclave a mixture consisting of 3grams of NH NO 2 grams of K HPO 2.5 grams of KH PO 2 grams of MgSO .7HO, 20 grams of Bacto-agar, and 1.0 liter of water. After the bottles andtheir contents had been sterilized in an autoclave for 20 minutes at 15pounds pressure and C., they were placed on their sides. As they cooled,the agar hardened. A sterile piece of filter paper for the culture tofeed upon was placed on top of the medium. Over its surface was spread 1to 2 cc. of the inoculum of Chaetomium globosum prepared as describedabove. The bottles, thus prepared, were held at an incubationtemperature of about 85 F. for 3 to 4 days, until a mycelial matdeveloped. On top of this mat was placed a sample of treated cottonduck, which had been leached in water for 24 hours in order to extractwater-soluble preservatives that would be removed normally by rain orother weather conditions. Over this fabric, more inoculum was spread.After 14 more days at about 85 F. the fabric was removed, washed free offungi, dried and tested for breaking strength.

Water repellency test The water spray test, Standard Test Method 22-41,1950 Technical Manual and Yearbook of the American Association ofTextile Chemists and Colorists, was used for determining waterrepellency. In this test, a specimen stretched tightly in a six-inchembroidery hoop, is held at a 45 angle six inches below a standard sprayhead. After pouring 250 cc. of water through the spray head the fabricis rated with respect to its water repellency. Ratings are made on ascale of zero to 100 where zero represents complete wetting of upper andlower surfaces and 100 represents complete absence of wetting. A ratingof 50 indicates complete wetting of upper fabric surface, 70 signifiespartial wetting of upper surface, 80 represents partial wetting to givea sharp spray head pattern, and 90 indicates slight random wetting ofupper surface.

Weathering test In this test, reduction of tensile strength isdetermined of samples of fabric that have been exposed to outsideatmospheric conditions for 30 days.

EXANCPLE 1 A piece of ounce cotton duck was immersed in an isopropylalcohol solution containing 3 percent by weight ofpoly-2-methyl-5-vinylpyridine, prepared as described in Table A, forsutficient time to effect thorough wetting. The fabric was then removed,freed of excess solvent, and immersed in an aqueous solution of cupricsulfate, whereupon an insoluble reaction product of the polymer with thecupric sulfate was precipitated in and/or on the fabric. The fabric wasthen leached with water for 24 hours to remove any uncombined metal saltand thus eliminate its effect on the subsequent tests. The fabric wasdried at 60 C. and tested by exposure to cultures of Chaetomium globosumfor 14 days as described above. The tensile strength of the fabric atthe end of this time was 46% of its original strength. By comparison theuntreated fabric after the same exposure retained only 4 /2 of itsoriginal tensile strength.

EXAMPLE 2 A butadiene-methylvinylpyridine copolymer, prepared asdescribed in Table A, was dissolved in a mixture of isopropyl alcohol,acetic acid, and water to form an aqueous solution containing 2%polymer, 10% acetic acid and 20% isopropyl alcohol (percent by Weight).The method of preparing this solution was as follows: The polymer. cutin small pieces, was let stand about one day in contact with a mixturecomprising one-half the total quantity of glacial acetic acid andisopropyl alcohol. At the end of this time, increments of the remainingalcohol and acid containing increasing amounts of water were added, withagitation, until the last addition was water alone.

, A sample of 10 ounce cotton duck was immersed in this solution for atime suificient to effect thorough wetting; After it had been squeezedbetween rollers to remove excess moisture, it was immersed in an aqueoussolution of cupric sulfate. Following the removal of excess moisture, itwas immersed in a dilute aqueous sodium bicarbonate solution in order toprecipitate on and/or in the fabric the insoluble copolymer-copper saltcomplex. The fabric was then leached in water for 24 hours and dried at60 C.

A sample of this fabric was leached in water for 24 hours to remove anyresidual metal salt. The sample was then tested for water repellency andresistance to deterioration paused by Chaetomium globosum, moist 10soil, and outdoor atmospheric conditions. found to be much superior toan untreated fabric. Results are given in Table I below:

They were sample of 1 Pounds pull per one inch width of test strip.

EXAMPLE 3 A copolymer of 1,3-butadiene and 2-methyl-5-vinylpyridine,prepared according to the recipe of Table A, was dissolved in anisopropyl alcohol-water HCl mixture to yield a solution comprising 1.5percent by weight of polymer hydrochloride, 35 percent isopropylalcohol, and the balance water. The following procedure was used toeffect solution: The polymer, cut in small pieces, was let stand aboutone day in contact with concentrated hydro chloride acid and aboutone-half the total quantityof isopropyl alcohol. Suflicient hydrochloricacid was used to combine with all of the basic nitrogen atoms in thepolymer. Water and the remaining alcohol were then added, withagitation, in increments containing increasing amounts of water, untilthe last addition was water alone.

A sample of 10 ounce cotton duck was immersed in this solution. After ithad been squeezed between rollers to remove excess moisture, it wasimmersed in an aqueous solution of cupric chloride. An insolublecopolymercopper salt complex was precipitated on and/or in the fabric.The fabric was then squeezed, immensed in dilute aqueous sodiumbicarbonate solution, leached in water for 24 hours, and dried at 60 C.

Samples of this fabric when tested for mildew resistance by the methoddescribed above were found to have retained 96% of their originaltensile strength as com pared to a retention of only 4 /2% of originaltensile strength by the untreated sample after the same test.

EXAMPLE 4 A sample of 10 ounce cotton duck was immersed in the solutionof a copolymer of 1,3-butadiene and Z-methyl-S vinylpyridine, preparedby the recipe of Table A. It was then squeezed, immersed in an aqueoussolution of ZnCl leached with water for 24 hours and dried at 60 C. Aninsoluble copolymer-zinc chloride complex was precipitated on and/ or inthe fabric.

Samples of this fabric when tested for mildew resistance by the methoddescribed above were found to have retained 81% of their originaltensile strength as compared to a retention of only 4 /z% of originaltensile strength by the untreated fabric after the same test.

EXAMPLE 5 A copolymer of 1,3-butadiene and Z-methyl-S-vinylpyridine,prepared according to the recipe of Table A, was dissolved by the methoddescribed in Example 2 to produce an aqueous solution containing 1.5%polymer, 5% acetic acid, .and 10% alcohol (percent by weight). A sampleof 10 ounce cotton duck was immersed in this solution. After it had beensqueezed between rollers to remove excess moisture, it was immersed inan aqueous solution containing /2 mol of zinc acetate for each nitrogenatom in one mol of the polymer. Following removal of excess moisture, itwas immersed in a dilute sodium bicarbonate solution in order toprecipitate on and/or in the fabric the insoluble copolymer-zinc acetatereaction product. The fabric was then leached in water for 24 hours, anddried at 60 C.

Y in the fabric.

gamete 11 Samples of this fabric when tested for mildew resistance bythe method described above it was found to have retained 100% of itsoriginal tensile strength, as against 4 /2% for the untreated fabricunder the same conditions. 1

EXAMPLE 6 Poly-2-methyl-5-vinylpyridine, prepared according to therecipe of Table A, was dissolved in an aqueous solution of hydrochloricacid in the proportion of grams of polymer per 100 cc. of the solution.Sufiicient hydrochloric acid was used to effect complete neutralizationof the polymer. A sample of -ounce cotton duck was immersed in thepolymer solution, squeezed to remove the excess solution, washed with0.05 N sodium hydroxide solution, rinsed, leached in water for 24 hours,and dried at 60 C. After a soil burial test for 30 days duration, thefabric was severely attacked by fungus. It was only slightly better thanthe untreated fabric.

EXAMPLE 7 V PolyZ-methyl-S-Vinylpyridine was dissolved in anapproximately 1.5% aqueous hydrochloric acid solution in the proportionof 5 grams of polymer/ 100 cc. of solution. A piece of 10-ounce cottonduck was immersed in the polymer solution, squeezed to remove excesssolution, and then immersed in a saturated solution of mercuricchloride. (Prior to being immersed in mercuric chloride solution, apiece thus treated contains approximately 7 percent by weight of polymerbased on the weight of the fabric.) By this method the complex of theacid salt of the polymer and the mercuric chloride was precipitated Thiscomplex contained 57.5 percent mercury by weight. The fabric wassqueezed to remove excess mercuric chloride solution, leached with waterfor 24hours, and dried at 60 C. It was buried in soil for 30 days at 30C. The fabric retained its tensile strength and showed only very slightdiscoloration at the end of this period, thus demonstrating that it washighly resistant to the action of soil organisms. A separate piece whichhad been treated with the Z-methyl-S-vinylpyridine polymer and mercuricchloride was tested and found to be water repellent.

EXAMPLE 8 A sample of 50/50 butadiene/2-methyl-5-vinylpyridine copolymerwas dissolved in an approximately 5% aqueous hydrochloric acid solutionin the proportion of 1.5 grams of copolymer/100 cc. of solution. (Alarge excess of hydrochloric acid was used in order to facilitatesolution of the copolymer.) A piece of 10-ounce cotton duck was immersedin the copolymer solution and then squeezed to remove the excess. Fabricthus treated contains approximately 2.2 percent by weight of polymer,based on the weight of the fabric. The fabric was then immersed in asaturated solution of mercuric chloride, squeezed to remove the excess,leached with water for 24 hours, and dried at 60 C. The complex of theacid salt of the polymer and the mercuric chloride contained 48 percentmercury by weight. Results of the soil burial test were the same as inExample 7. The fabric was also water repellent.

EXAMPLE 9 A sample of the 50/50 butadiene/Z-methyl-S-vinylpyridinecopolymer prepared as described in Table A was dissolved in aqueousacetic acid, mercuric acetate was added (an amount equivalent to one molof mercuric acetate per pyridine nucleus in the copolymer), and themixture was heated minutes at 85 C. The final solution contained 1.5%copolymer, 15% acetic acid, and 2%. merc-uric acetate. A piece of10-ounce cotton duck was immersed in this solution, squeezed to removethe excess, and then washed with 0.05 N sodium hydroxide, leached withwater for 24 hours, and dried at 60 C. The mercurated polymer contained40.2% mercury by weight.

Results of the soil burial test were the same as (7) and (8) and thefabric was water repellent.

EXAMPLE 10 A piece of 10-ounce cotton duck was immersed in a saturatedsolution of mercuric chloride, squeezed to re move the excess solution,water leached, and dried. The fabric showed no water repellency. Afterthe soil burial test, the fabric was disintegrated more than that ofExample 6. It was attacked by fungus but not so severely as that ofExample 6.

EXAMPLE 11 An untreated piece of 10-ounce cotton duck was subjected tothe soil burial test. At the end of 30 days there was severe tenderingof the fabric, i. e., it showed a substantial amount of disintegration.It could not be removed from the soil in one piece. It was severelyattacked by fungus.

EXAMPLE 12 In order to demonstrate that it is the mercury in thepolymeric product which prevents fungus attack, pieces of absorbentpaper were immersed in an 8 percent solution ofpoly-2-methyl-5-vinylpyridine which had been percent neutralized withhydrochloric acid. While these papers were still wet they were immersedin a saturated solution of mercuric chloride to precipitate the mercuricchloride-polymer hydrochloric complex. Fungicidal activity wasdetermined by an infected wheat test in which wheat infected principallywith Helminthosporum sativum was placed upon the paper. The test wasmade upon freshly prepared paper, paper soaked over night in water,paper exposed out of doors for one week, and paper impregnated with thepolymer hydrochloric containing no mercury. In each case 10 infectedseeds were placed upon the paper and the seeds were incubated for 15days in a constant temperature atmosphere. Results of these tests aretabulated below:

The amount of mercury present in the polymeric material may vary betweenwide limits. This mercury should comprise from 5 to 58% (preferably10-58%) by weight of the polymeric treating material, and preferably themercuric salt reaction product with the pyridine derivative polymershould contain at least 30 percent mercury by weight. As previouslystated, the other metals should comprise at least 5% by weight of thepolymeric treating material.

As many possible embodiments may be made of this invention withoutdeparting from the scope thereof it is to be understood that all matterherein set forth is to be interpreted as illustrative and not in alimiting sense.

I claim:

1. The method of preparing an impregnant for absorbent materialcomprising preparing a solution of a polymer of a monomer systemcomprising a compound having a structure selected from the groupconsisting of and where R is selected from the group consisting ofhydrogen, alkyl, vinyl, alpha-methylvinyl, nitro, alkoxy, halo, hydroxy,cyano, aryloxy, aryl, haloalkyl, alkylaryl, and hydroxyaryl, at leastone and not more than two of said groups being selected from the groupconsisting of vinyl and alpha-methylvinyl; and the total number ofcarbon atoms in the nuclear substituted groups being not greater than12, in addition to those carbon atoms in the vinyl and alpha-methylvinylgroups; and mixing a solution of a heavy metal salt with said polymersolution to produce a water-insoluble addition product of the salt withthe polymer, said product containing at least metal by weight.

2. Process of claim 1 wherein the metal is selected from the groupconsisting of mercury, copper, zinc, chromium, and cadmium.

3. The method of preparing an impregnant for absorbent materialcomprising preparing an acid solution of a polymer of a monomer systemcomprising a compound having a structure selected from the groupconsisting of and where R is selected from the group consisting ofhydrogen, alkyl, vinyl, alpha-methylvinyl, nitro, alkoxy, halo, hydroxy,cyano, aryloxy, aryl, haloalkyl, alkylaryl, and hydroxyaryl, at leastone and not more than two of said groups being selected from the groupconsisting of vinyl and alpha-methylvinyl; and the total number ofcarbon atoms in the nuclear substituted groups being not greater than12, in addition to those carbon atoms in the vinyl and alpha-methylvinylgroups; and mixing the resulting solution with a mercuric salt solution,whereby a waterinsoluble addition product of the polymer with themercury salt is formed, said product containing -58% mercury by weight.

4. Process of claim 3 wherein the acid is HCl, the mercuric salt isselected from the group consisting of mercuric chloride and mercuricnitrate, and said polymer is and Where R is selected from the groupconsisting of hydrogen, alkyl, vinyl, alpha-methylvinyl, nitro, alkoxy,halo, hydroxy, cyano, aryloxy, aryl, haloalkyl, alkylaryl, andhydroxyaryl, at least one and not more than two of said groups beingselected from the group consisting of vinyl and alpha-methylvinyl; andthe total number of carbon atoms in the nuclear substituted groups beingnot greater" than 12, in addition to those carbon atoms in the vinyl andalpha-methylvinyl groups; the resulting product be ing water-insolubleand containing at least 5% metal by weight.

7. Composition of claim 6 wherein the metal is selected from the groupconsisting of copper, mercury, zinc, chromium, and cadmium.

8. As a new composiiton of matter, the reaction product of a mercuricsalt with a polymer of a monomer system comprising a compound having astructure selected from the group consisting of and where R is selectedfrom the group consisting of hydrogen, alkyl, vinyl, alpha-methylvinyl,nitro, alkoxy, halo, hydroxy, cyano, aryloxy, aryl, haloalkyl,alkylaryl, and hydroxyaryl, at least one and not more than two of saidgroups being selected from the group consisting of vinyl andalpha-methylvinyl; and the total number of carbon atoms in the nuclearsubstituted groups being not greater than 12, in addition to thosecarbon atoms in the vinyl and alpha-methylvinyl groups; the reactionbeing carried out in the presence of an acidic solution, the reactionproduct being water-insoluble and containing 10 to 58 percent mercury byweight.

9. The composition of claim 8 in which said mercuric salt is mercuricacetate and said acid is acetic acid.

10. The composition of claim 8 in which said mercuric salt is selectedfrom the group consisting of mercuric chloride and mercuric nitrate andsaid acid is hydrochloric acid.

11. The method of rendering absorbent material water repellent andresistant to attack by parasitic microorganisms comprising impregnatingsaid material with the reaction product of a solution of a heavy metalsalt and a solution of a polymer of a monomer system comprising acompound having a structure selected from the group consisting of whereR is selected from the group consisting of hydrogen, alkyl, vinyl,alpha-methylvinyl, nitro, alkoxy, halo, hydroxy, cyano, aryloxy, aryl,haloalkyl, alkylaryl, and hydroxyaryl, at least one and not more thantwo of said groups being selected from the group consisting of vinyl andalpha-methylvinyl; and the total number of carbon atoms in the nuclearsubstituted groups being not greater than 12, in addition to thosecarbon atoms in the vinyl and alpha-methylvinyl groups; the reactionproduct containing at least metal by weight, whereby from 0.1 to 25parts by weight of water-insoluble reaction product is deposited per 100parts by weight of the dry absorbent.

12. A method of rendering absorbent material water repellent andresistant to attack by parasitic microorganisms according to claim 11wherein said heavy metal is selected from the group consisting ofmercury, copper, zinc, chromium and cadmium.

13. The method of rendering absorbent material water repellent andresistant to attack by parasitic microorganisms, comprising contactingsaid material with an acid solution of a polymer of a monomer systemcomprising a compound having a structure selected from the groupconsisting of and R LNjR where R is selected from the group consistingof hydrogen, alkyl, vinyl, alpha-methylvinyl, nitro, alkoxy, halo,hydroxy, cyano, aryloxy, aryl, haloalkyl, alkylaryl, and hydroxyaryl, atleast one and not more than two of said groups being selected from thegroup consisting of vinyl and alpha-methylvinyl; and the total number ofcarbon atoms in the nuclear substituted groups being not greater than12, in addition to those carbon atoms in the vinyl and alpha-methylvinylgroups; contacting said material thereafter with a solution of amercuric salt, thereby precipitating from 0.5 to 5 parts by weight of awaterinsoluble mercuric salt-polymer addition product in said materialper parts by weight of dry material, and rinsing and drying the treatedmaterial.

14. An absorbent article impregnated with the reaction product of aheavy metal salt and a polymer of a monomer system comprising a compoundhaving a structure selected from the group consisting of and where R isselected from the group consisting of hydrogen, alkyl, vinylalpha-methylvinyl, nitro, alkoxy, halo, hydroxy, cyano, aryloxy, aryl,haloalkyl, alkylaryl, and hydroxyaryl, at least one and not more thantwo of said groups being selected from the group consisting of vinyl andalpha-methylvinyl; and the total number of carbon atoms in the nuclearsubstituted groups being not greater than 12, in addition to thosecarbon atoms in the vinyl and alpha-methylvinyl groups; said reactionproduct-con- 17 taining at least 5% metal by weight and being depositedin an amount of 01-25 parts by weight per 100 parts by weight of dryabsorbent.

15. An article of claim 14 wherein said heavy metal is selected from thegroup consisting of mercury, copper, zinc, chromium and cadmium.

16. An article of claim 14 wherein said heavy metal is copper and saidpolymer is a copolymer of 1,3-butadiene and 2-methy1-5-viny1pyridine.

17. An article of claim 14 wherein said heavy metal is zinc and saidpolymer is a copolymer of 1,3-butadiene and Z-methyLS-vinylpyridine.

18. An absorbent article impregnated with the reaction product of amercuric salt and a substituted pyridine polymer, at least one and notover two substituent groups being vinyl, any additional substituentsbeing alkyl radicals selected from the group consisting of methyl andethyl radicals, said reaction being carried out in the presence of anacidic solution, said reaction product being water-insoluble andcontaining -58% mercury by weight based on the weight of dry absorbent,the impregnant being deposited in an amount of 0.5-5 parts by weight per100 parts by Weight of absorbent and functioning to render the articlewater repellent and resistant to fungi and insects.

19. The article of claim 18 in which said polymer is prepared from amonomeric mixture containing a vinylpyridine and not over 75 parts byweight, per 100 parts of monomers, of a copolymerizable conjugateddiene.

20. The article of claim 18 in which said polymer is prepared bypolymerizing a mixture containing 0 to 75 parts by weight of butadieneand 100 to 25 parts by weight of 2-methyl-5-vinylpyridine per 100 partsof total monomers.

21. As a new composition of matter, the reaction product of a mercuricsalt with a polymer of a monomer system comprising a substitutedpyridine base monomer, at least one and not more than two substituentgroups being selected from the group consisting of vinyl andalpha-methylvinyl, any additional substituents being 18 alkyl radicalshaving in combination a total of not more than 12 carbon atoms, thereaction being carried out in the presence of an acidic solution, andthe resulting product containing 10 to 58 percent mercury by weight.

22. The method of preparing an absorbent material treating agent whichcomprises preparing an acid solution of a polymer of a monomer systemcomprising a substituted pyridine base monomer, at least one and notmore than two substituent groups being selected from the groupconsisting of vinyl and alpha-methylvinyl, any additional substituentsbeing alkyl radicals having in combination a total of not more than 12carbon atoms, contacting the resulting solution with a solution ofmercuric salt, and recovering the resulting product, said productcontaining 10 to 58 percent mercury by weight.

23. The method of rendering absorbent material resistant to attack bybacteria, fungi, insects and their larva, which comprises impregnatingsaid material with the reaction product of a mercuric salt and a polymerof a monomer system comprising a substituted pyridine base monomer, atleast one and not over two substituent groups being selected from thegroup consisting of vinyl and alpha-methylvinyl, any additionalsubstituents being alkyl radicals having in combination a total of notmore than 12 carbon atoms, said reaction being carried out in thepresence of an acidic solution, the reaction product containing 10 to 58percent mercury by weight.

References Cited in the file of this patent UNITED STATES PATENTS2,390,408 Young Dec. 4, 1945 2,471,261 Cook May 4, 1949 2,487,829Richards Nov. 15, 1949 2,604,668 Miller July 29, 1952 2,658,850 CislakNov. 10, 1953 2,702,763 Pritchard Feb. 22, 1955 2,751,323 Pritchard eta1. June 19, 1956 2,767,159 Potts Oct. 16, 1956

11. THE METHOD OF RENDERING ABSORBENT MATERIAL WATER REPELLENT ANDRESISTANT TO ATTACK BY PARASITIC MICROORGANISMS COMPRISING IMPREGNATINGSAID MATERIAL WITH THE REACTION PRODUCT OF A SOLUTION OF A HEAVY METALSALT AND A SOLUTION OF A POLYMER OF A MONOMER SYSTEM COMPRISING ACOMPOUND HAVING A STRUCTURE SELECTED FROM THE GROUP CONSISTING OF